Posterior Vitreous Detachment

Question 1

Symptoms of PVD?

Answer 1

• Floaters
  o Described as “cobwebs”
• Flashes
  o Single transient flashes in periphery
  o Not like fortification spectra
• None
  o Many are asymptomatic

Question 2

Signs of PVD?

Answer 2

• Weiss ring
  o Pathognomonic for vitreous separation
  o Formed from ring of glial tissue on posterior hyaloid face that surrounds optic disc
  o Often incomplete – usually not an obvious ring
  o Lies in front of retina so will not see it if the view of retina is in perfect focus e.g. fundus photograph
   Focus in front of retina to identify it
  o Best seen with:
   Bright light
   Slightly oblique
   In front of and below disc
• Posterior hyaloid face
  o May be seen as a crinkly, transparent grey membrane behind lens

Question 3

What are the +ves & -ves of a PVD occurring?

Answer 3

• +ves:
  o Reduces risk of macular hole formation
  o Eliminates risk of proliferative diabetic retinopathy
• -ves:
  o Risk of retinal break and detachment
  o 8-12% risk of break in symptomatic PVD

Question 4

Examination carried out in PVD?

Answer 4

• In any patient who has a symptomatic vitreous separation, it’s essential to detect any retinal breaks before they cause a retinal detachment
• Fully dilated pupil
• Wide-field, non-contact examination with 90D or “super field” lens
• Peripheral (360°) indentation with binocular indirect ophthalmoscope is valuable
• 3-mirror Goldmann Contact Lens – placed on cornea – may cause corneal haze – making it harder to identify and treat retinal breaks
  o Equatorial mirror (largest & oblong) – from 30 to equator
  o Peripheral mirror (square) – from equator to ora serrata
  o Gonioscopic (smallest)

Question 5

How to detect a retinal tear & why do some people who have PVD get a retinal tear?

Answer 5

• If retina tears, RPE cells will be exposed and will migrate into vitreous & may be visible as pigmented specks
  o Schafer’s sign
  o Strongly correlated with presence of retinal breaks
  o Absence of Schafer’s sign DOES NOT exclude a retinal break
• Pxs who have symptomatic vitreous separation may develop a retinal tear and most of these will progress to retinal detachment if left untreated
• Vitreous is firmly adherent to retina at vitreous base
• If there is a posterior extension of vitreoretinal adhesion, due to lattice degeneration for e.g., there is an increased risk of a retinal tear when vitreous separates
• Mechanical traction of vitreous is not evenly distributed round whole of vitreous base, but is concentrated at edge of posterior extension leading to a horseshoe tear

Question 6

Treatment for PVD?

Answer 6

• Pxs who were symptomatic will find their symptoms will improve over a few months
• Small minority will continue to have severe symptoms of floaters
  o Only effective treatment: Vitrectomy
  o Other treatments have been proposed:
   YAG vitreolysis (blowing up floaters)
   Exercises
   Special diets

Question 7

Management for PVD?

Answer 7

ADVICE:
Relate back to H&S
Describe findings/results of tests
Describe condition, including: what it is, cause, prognosis
Discuss management options (if applicable)

MANAGEMENT:
Explain all management options
Explain to px what will happen next

REFERRAL?

RECALL:
Details of when need to see px back
Also include details e.g. if see flashes of light and more floaters - return